Korean architecture classifies Banja (the decorated flat of the ceiling visible from the inside) of Royal Palaces into two types: Woomul(water-well, 井) banja, which inserts rectangular wooden board into lattice frame, and paper banja, which applies paper to the flat ceiling. Such classification was established in the 19th century. Before that, Banja was classified according to what was inserted into the lattice frame, either wooden or paper board. At first, the banja that used paper board was widely installed regardless of the purpose or nobility of the building. However, since the 17th century, the use of paper board banja became mostly restricted to Ondol (Korean floor heating system) rooms which are characterized by private usage and the importance of heating, and it was considered inferior to wooden board banja in terms of rank or grace. The contemporary paper banja was mainly installed in low-rank ondol rooms until the late 19th century to early 20th century, when roll-type wallpaper was introduced from the West and the paper banja came to decorate the King’s and Queen’s bedrooms. The traditional paper board banja benefits heat reservation, reduces the weight of the ceiling, and allows the adjustment of the lattice frame size. Furthermore, it can feature unique artistry if covered with blue, white, or red Neung-hwa-ji (traditional flower pattered paper).

This paper examines the seismic performance and structural design of the ceiling bracket-type modular connection. The bracket-type system reduces the cross-sectional area loss of members and combines units using fitting steel plate, and it has been developed to be fit for medium-story and higher-story buildings. In particular, this study conducted the cyclic loading test for the performance of the C-type and L-type brackets, and compared the results. The test results were also compared with the commercial FEA program. In addition, the structural design process for the bracket-type modular connection was presented. The two connections, proposed as a result of the test results, were all found to secure the seismic performance level of the special moment steel frame. In the case of initial stiffness, the L-type bracket connection was found to be great, but in the case of the maximum moment or fully plastic moment, it was different depending on the loading direction.

소형선박 기관실 내 화재 시 개구부 유동 및 온도에 대해 FDS(Fire Dynamics Simulator)를 이용하여 화재시뮬레이션을 수행하였다. 열방출률이 10 kW 급인 경유(Diesel) 화재를 대상으로 하였고, 천장 통풍통의 위치, 측면 개구부 유·무 및 크기에 대한 영향을 파악하였다. 측면 개구부의 유·무 및 크기는 연기 거동 뿐 아니라 개구부를 통한 질량 유량 및 온도에 지대한 영향을 미쳤다. 측면 개구부가 미설치되거나 크기가 작은 경우 연기층이 기관실 내 바닥까지 도달하였고, 측면 개구부의 크기가 증가함에 따라 개구부를 통한 질량 유량이 증가하고 온도는 감소하는 경향이 나타났다. 반면, 천장 통풍통의 위치가 연기 거동, 개구부를 통한 질량 유량 및 온도에 미치는 영향은 측면 개구부 크기에 비해 상대적으로 미미한 것으로 관찰되었다. 따라서 소형선박의 기관실 내 화재 시 안전성 향상을 위해서는 천장 통풍통 위치보다 측면 개구부의 크기가 더 중요한 설계 인자인 것으로 판단된다.

본 연구는 거제도에 분포하는 난대림대의 식물군집구조 특성을 파악하기 위하여, 교목층, 아교목층, 관목층에 상록활엽수가 우점하거나 분포하는 천장산 북동사면을 대상으로 조사구를 설정하였다. 조사구는 상록활엽수가 분포하는 능선, 계곡, 경사지 등 천장산을 대표할 수 있는 식생군락과 입지환경의 변화가 있는 지역을 대상으로 31개소의 방형구를 설치하였다. TWINSPAN에 의한 군락분류 결과, 참식나무-굴피나무, 참식나무-때죽나무, 참식나무-참회나무, 곰솔-참식나무, 참식나무- 졸참나무, 굴참나무-굴피나무 6개 군락으로 구분되었다. 난대림의 천이경향에 의하면, 곰솔, 낙엽활엽수를 거쳐 상록활엽수로 진행된다라는 연구결과를 반영한다면, 곰솔군락 뿐만 아니라 졸참나무, 굴피나무, 굴참나무 등 낙엽활엽수가 우점하거나 경쟁하는 지역도 참식나무가 우점하는 상록활엽수로 천이가 진행될 것이다. 환경요인과 식생분포간의 관계를 살펴보면, 경사 도, Na+, K+, 전기전도도, 물리적 특성 중 점토(clay) 등이 식생분포에 직간접적인 영향을 미치는 것으로 분석되었다.

2017년 발생한 포항 지진으로 인하여 천장재, 외장재, 커튼월 등 비구조재의 파괴에 의한 피해가 다수 보고되었으며 비구조재의 내진설계가 중요해지고 있다. 본 연구에서는 임팩트해머 테스트를 통해 행어볼트 길이에 따른 천장재의 고유진동수와 감쇠비를 식별하였다. 또한 천장재가 벽 또는 다른 구조체에 충돌하는 경우 발생하는 충격효과를 정확히 고려하기 위해 충돌실험을 수행하였다. 식별된 천장재의 동특성과 충격지속시간을 바탕으로 실제로 천장재가 지진하중으로 인하여 주변 구조물과 충돌이 발생하는 경우에 대한 천장재 응답특성을 수치해석을 통하여 분석하였다. 수치해석 시뮬레이션 결과, 충격하중은 이격거리에 따라 선형적으로 증가하는 경향을 보였으며, 달대길이와는 무관한 것으로 나타났다.

In the current research, a seismic ceiling system as one of non-structural elements in buildings has been developed by applying newly designed vertical hanger clips combined with M-bar channel clips. In order to evaluate the seismic performance of the developed system, full-scale shaking table tests of one story frame structure with the conventional ceiling system or the developed seismic ceiling system were performed with time-history responses under earthquake loads. The developed system was also evaluated by the time-history dynamic analysis. From seismic test and analysis, it was shown that the developed seismic ceiling system could give improved seismic performances to minimize displacements and damages of ceiling systems as well as enhance seismic safety of the ceiling system.

With increasing public awareness regarding radon, this study has been conducted with the aim of providing more accurate information about radon to the public. We investigated the radon emissions from gypsum boards, which are known to emit relatively higher levels of radon among the building materials available on the market. Radon emissions were measured over three weeks using the closed chamber method with nuclear track detectors. For ceiling materials, the arithmetic mean of the radon emissions was 43.8 ± 42.2 Bq/m3 (geometric mean: 28.9 ± 5.6), 156.2 ± 150.5 mBq/m2/h per unit area (geometric mean, 103.1 ± 2.7) and 21.1 ± 19.9 mBq/kg/h per unit mass (geometric mean: 14.4 ± 2.6). Regarding the wall materials, the arithmetic mean of radon emissions was 24.1 ± 24.0 Bq/m3 (geometric mean: 15.6 ± 2.6), 133.3 ± 143.4 mBq/m2/h per unit area (geometric mean, 76.8 ± 3.0) and 13.0 ± 10.4 mBq/kg/h per unit mass (geometric mean, 9.5 ± 2.3). According to the results of this study, higher radon concentrations and emissions were detected in the ceiling materials than in the wall materials, but these values were lower than those previously measured in building materials.

The pelvic compression belt (PCB) contributes to improving sacroiliac joint stability, and it has been used as an additional therapeutic option for patients with sacroiliac joint pain (SIJP). This study aimed to investigate whether the muscle activation patterns of the supporting leg was different between asymptomatic subjects and subjects with SIJP during one-leg standing, and how it changes with the PCB. 15 subjects with SIJP and 10 asymptomatic subjects volunteered to participate in this study. Surface electromyography (EMG) data (reaction time [RT] and muscle activation) were collected from the internal oblique, lumbar multifidius, gluteus maximus and biceps femoris muscles during one-leg standing with and without the PCB. Without the PCB condition, in the SIJP group, the biceps femoris muscle showed the fastest RT among all muscles (p<.05), whereas in the asymptomatic group, the RT of the internal oblique muscle was the most rapid (p<.05). In condition without the PCB, the biceps femoris EMG amplitudes in the SIJP group were significantly greater than that in the asymptomatic group (p<.05). After the application of the PCB, the RT of the biceps femoris muscle was significantly increased only in the SIJP group (p<.05). Moreover, the biceps femoris EMG amplitudes significantly decreased and the gluteus maximus EMG amplitudes significant increased only in the SIJP group by applying the PCB (p<.05). However, this had no such effect on the gluteus maximus and biceps femoris EMG patterns in the asymptomatic group (p>.05). Thus, this study supports the applying the PCB to patients with SIJP can be used as a helpful option to modify the activation patterns of the gluteus maximus and biceps femoris muscle.

Overhead facility design problem(OFDP) is one of the shortest rectilinear flow network problem(SRFNP)[4]. Genetic algorithm(GA), artificial immune system(AIS), population management genetic algorithm (PM) and greedy randomized adaptive search procedures (GRASP) were introduced to solve OFDP. A path matrix formed individual was designed to represent rectilinear path between each facility. An exchange crossover operator and an exchange mutation operator were introduced for OFDP. Computer programs for each algorithm were constructed to evaluate the performance of algorithms. Computation experiments were performed on the quality of solution and calculations time by using randomly generated test problems. The average object value of PM was the best of among four algorithms. The quality of solutions of AIS for the big sized problem were better than those of GA and GRASP. The solution quality of GRASP was the worst among four algorithms. Experimental results showed that the calculations time of GRASP was faster than any other algorithm. GA and PM had shown similar performance on calculation time and the calculation time of AIS was the worst.

Recently, functional building materials have been developed and introduced to the market. Many building materials emit volatile organic compounds(VOCs) which have the potential to affect health and comfort, and moisture problem has a major role also being established in indoor air quality (1AQ) problems. The purpose of this study is to evaluate the performance of reduction of HCHO using the gupsum board and water vapour adsorption/desorption property for ceiling board for mock-up test room and test house. The mock-up test is conducted according environmental standard method for indoor air quality of the ministry of environment. The results of this study are as follows, the reduction of HCHO gypsum boards are showed an effect to reduce the formaldehyde(HCHO) concentration of mock-up test room and test house. The indoor humidity is also showed to be lower than the general ceiling materials, since there is increased in the absorbed indoor humidity by using a humidifier with moisture adsorption/desorption ceiling materials. In natural conditions, moisture adsorption/desorption ceiling materials is showed a higher humidity than general ceiling materials constructed in the mock-up test room. However It changes of moisture adsorption/desorption is not appeared in test house. Therefore, in case of decreasing and increasing in humidity, these materials can be offset by reduction of HCHO using the gypsum board.

최근 지하철 역사 내의 사고위험을 줄이기 위해 승강장에 스크린도어(PSD; Platform Screen Door)를 설치하는 사례가 늘고 있다. 일반적으로 지하철역사와 같이 폐쇄된 공간에 있어서 유동장의 해석 및 예측은 전산유체해석 (CFD: Computational Fluid Dynamics)을 주로 사용한다. 그러나, CFD는 실제로 열차가 주행할 때에 발생하는 비정상적(unsteady)인 유동장의 3차원적인 해석에는 승강장의 세부적인 형태의 모델링이 어렵기 때문에 어느 정도의 한계가 있다. 따라서, 본 연구에서는 밀폐형 스크린도어가 설치된 지하승강장을 대상으로 직통열차에 의한 스크린도어 및 승강장 천장마감재에 작용하는 풍압을 계측하였다. 계측된 풍압으로부터 스크린도어의 구조안전성을 위한 설계풍압을 결정하고, 승강장 내부의 천장마감재에 작용하는 풍압을 평가하여 승강장의 안전한 풍환경을 확보하는데 기초적인 자료를 제시하였다.

140 buildings of Korean major cities were investigated for the presence of asbestos and man made mineral fibers (MMMF) in their construction materials. 73 (52%) and 84 (60%) buildings contained asbestos and MMMF in their construction materials, respectively, and 17 (12%) buildings contained both asbestos and MMMF. 75% of the asbestos containing buildings were mostly constructed during 1970's. 100% of underground shopping arcades, 90% of manufacturing workplaces, 84% of train and bus terminals had the asbestos containing construction materials. The manufacturing workplaces of Daejeon (89%) and Daegu (89%), which mostly had been built in the past, used asbestos containing building materials, while the building in Seoul, Busan and Jinju, which were constructed recently, used relatively lower asbestos containing building materials with 46%, 28%, and 33%, respectively. 9 building materials that have been widely used in Korea were analyzed using a transmission electron microscope equipped with energy dispersive X-ray analyzer (TEM-EDX) for their mineral contents. All asbestos fibers showed typical characteristics of chrysotile fibers with hollow tube structure. The average diameter ranged from 0.03㎛ to 0.05㎛, and the average length were ranged from 7.5㎛ to 12.0㎛. Atomic percentages of asbestos fibers were 51.9∼55.9% of Mg, 41.3∼44.3% for Si, and 2.7∼4.8% for Fe.

본 연구는 포켓몬 시리즈의 남성/남성 지배 포켓몬들과 여성/여성 지배 포켓몬들의 특징을 분석하면서 포켓몬 시리즈의 성 지위에 대해 탐구한다. 1세대부터 8세대까지 802의 포켓몬 캐 릭터가 존재한다. 각 포켓몬들은 태어날 때 다른 성 비율을 지니고 있다: 하나의 포켓몬은 남 성, 여성, 동등, 무성의 “확률”을 지니고 있다. 본 연구를 이러한 포켓몬들은 3가지 기준으로 분 석 한다: 1) 출연 빈도 2) 능력 3) 종류의 다양성, 그리고 이것을 성별의 기준으로 비교한다. 포 켓몬 시리즈는 다른 비디오 게임과 다르게 다양한 캐릭터들을 제공한다. 그러므로 이는 사람들 이 비디오 게임 캐릭터들의 성 지위를 보다 깊고 의미 있게 볼 수 있도록 도와준다.

The techniques for seismic design and seismic reinforcement of structural members in Korea have beendeveloped in a wide variety of ways, but research and technology on seismic retrofitting methods of nonstructural materials are very inadequate. In this study, we analyze ceiling system products of Japan which have seismic performance as a basic study on the development of non-structural ceiling system.

This study evaluated displacement of ceiling system under lastic dynamic load. Main parameters are change of stiffness at connections of bolt and C channel ranged between 0.1~2.0 kN/mm. Program for elastic dynamic anaysis is the MIDAS ZEN. Analysis results showed that connections between bolt and C channel was effective on decreasing of displacement of ceiling system.